Damping device



N0v.5,196s RJGEHRUNG ETAL 3,409,339

DAMPING DEVICE Filed May 20, 1966 2 Sheets-Sheet l VENTORS F00/ ./T gf/@vue so .Z P//ap/r ,5y MMM ra/wea NOV. 5, 1968 R 1 GEHRUNG ET AL 3,409,339

DAMPING DEVICE 2 Sheets-Sheet Filed May 20, 1966 fda/f. 6

Unted States Patent O* 3,409,339 DAMPING DEVICE Rudi J.=Gehrung and Leo J. Rhoda, Indianapolis, Ind.,

assignors to Radio Corporation of America, a corporation of Delaware Filed May 20, 1966, Ser. No. 551,577 7 Claims. (Cl. 312-8) ABSTRACT OF THE DISCLOSURE In a portable equipment cabinet Which includes a pivotally mounted tray member, a brake member is provided for dampingthe pivotal movement of the tray when it is caused to move from a vertical position to a horizontal position.

This invention relates to damping devices and more particularly to a mechanism for damping the movement of a hinged cabinet member when the member pivots from a first position to a second position under the force of gravity. i

A portable equipment cabinet may include a tray member pivotally mounted to form a wall of the cabinet. Such a cabinet, for example, may be utilized to house sound reproducing apparatus, such as record player equipment, wherein one or more speaker doors form the front cover of the cabinet and a tray member housing a record player apparatus forms the rear cover of the cabinet. To place the record player apparatus in operating position, the speaker doors are pivoted outward into flanking relation to the cabinet side walls and the tray member is pivoted into a horizontal position extending through the opening defined by the cabinet side walls. Apparatus of this type is disclosed in co-pending application Ser. No. 517,380 and assigned to the same assignee as this application.

It has been observed that when the latch holding the tray in its vertical storage or closed position is released, the tray and associated record player apparatus may drop unrestrained to its horizontal operating position. Due to the weight of the tray and record changer such action may result in damage to the cabinet or the operating mechanism contained therein.

It is therefore an object of the present invention to provide a means for damping the movement of a pivotally mounted tray member forming a vertical wall of an equipment cabinet when said member is caused to be pivoted into its horizontal or operating position.

A portable equipment cabinet embodying the invention includes a pair of vertically spaced side walls pivotally mounting a tray member carrying a sound reproducing apparatus therein for movement from a vertical storage position to a horizontal operating position. An arcuately shaped track is secured to one of said side walls adjacent the tray pivot -mounting and in surrounding relation thereto. An arm member is journalled on said pivot mounting and coupled to said tray member for pivotal movement therewith. A shoe member is positioned for movement along said track and means including a spring are provided for coupling said arm to the shoe member and for urging said shoe into cooperative engagement with said track. The engagement between the shoe and the track develops a frictional force for damping the pivotal movement of said tray as it pivots from its vertical storage position to its horizontal operating position.

The novel features which are considered to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation will best be understood from the following description when considered in connection with the accompanying drawings in which:

FIGURE 1 is a front perspective view, partially broken away, of a portable phonograph and cabinet embodying the damping mechanism of the invention;

FIGURE 2 is a front elevation view of the cabinet damping mechanism shown in FIGURE l and with `the tray cabinet member in its vertical storage position;

FIGURE 3 is a View similar to FIGURE 2 but with the cabinet tray member midway between its vertical storage position and its horizontal operating position; and

FIGURE 4 is a view similar to FIGURE 2 but with the cabinet tray member shownin its horizontal operating position. i

In referring to the drawings, like elements and parts are designated by like reference characters throughout the ligures.

Referring now to FIGURE l, there is shown a perspective View of a portable record player 10 enclosed in a cabinet 12. The player apparatus 10 is supported in a tray 14 which is shown in its closed or tilt-up position, wherein the bottom wall (not shown) of the tray 14 provides a rear cover for the cabinet 12. The tray 14 is pivotally joined to the inside surface of opposing cabinet 12 side Walls 16 and 18 by means of brackets 20 and 22 and respective bearing pins 24 and 26. One of the speaker enclosures 28 is broken away and shown in its closed position covering a portion of the front of the cabinet 12, and the other speaker enclosure 30 is shown in its lateral open position in right lian-king relationship to the side Wall 16. Further details of construction of the cabinet 12 may be had by referring to the aforementioned copending application Ser. No. 517,380.

When the player apparatus 10 is placed in its operating position, the enclosure 28 is moved to its open position in left flanking relationship to side wall 18. Upon release of the latch 32, the tray member 14 carrying the player apparatus tilts downwardly about the pivot pins 24 and 26 -u-nder the force of gravity and comes to rest in a horizontal position in which it extends through the opening defined by the cabinet side walls 116 and 18. A stop 34 which moves with the tray member 14 into engagement with a portion of the side wall 18, is provided to limit the pivotal movement of the tray 14 to the aforesaid horizontal position.

To prevent the tray from slamming to its horizontal position when released, a forward or tilt down damping mechanism is provided to slow the tilt down pivotal speed. The mechanism includes a mounting plate 36 which is fixedly secured to the cabinet side wall 16 in the area of the pivot bearing 24. A track 38 having an arcuately contoured surface 40 is positioned on the mounting plate 36 and beneath the pivot bearing 24. The surface arc center is slightly offset from the bearing 24 center or axis such that its radius of curvature with respect to the bearing axis decreases when moving from left to right as viewed in FIGURE 2. The lower end of the track is loosely affixed to the plate 36 by means of a screw or rivet 42 and the upper end of the track is fastened to a bent over projection 44 of the plate .36 by means of a thu-mb screw 46 inserted through an elongated opening 47 in the projection 44. The screw 46 is adjustable to raise and lower the track, the track lower end pivoting about the rivet 42, and thereby changing its effective arc center with respect to the pivot bearing center to provide a gradually controllable friction curve in accordance with the invention as will be hereinafter described.

As shown more particularly in FIGURES 2, 3 and 4, an arm member 48 having a finger like portion 49 is journalled around the pivot bearing 24 and fastened to the tray bracket 20 for pivotal movement therewith by means of screws 50. A wedge shaped shoe 52 having an inclined top side 53 and a channeled `underside is positioned on the track forvmovement along its surface 40. The shoe channel includes a lining, such as a leather strip 54, to provide a desired coefficient of sliding friction between the track surface 40 and the shoe 52. The shoe 52 is resiliently supported by a U-shaped leaf spring S6 having its upper leg fastened to the arm 48 by means of a screw 58, and its lower leg fastened to the top side 53 of the shoe 52 by means of a rivet or screw 60. As the tray 14 is pivoted from its vertical closed position to its horizontal tilt-down or operating position, the tension of the spring is such that it holds the shoe lining 54 in frictional contact with the track surface 40, and the inclined shoe top side 53 in a wedge like engagement with the extended finger portion 49 of the arm 48, so that the linger 49 is caused to ride up the inclined shoe side 53, thereby increasing the frictional contact between the shoe lining 54 and track surface 40 and damping the pivotal movement of the tray 14. This is due to the decreasing radius of curvature of the track surface with respect to the pivot axis and the wedging action of the shoe 52 between the track surface 40 and the arm finger portion 49. This is illustrated in FIGURES 2, 3 and 4 wherein the movement of the tray and coupled shoe is shown in successive stages. When the tray 14 is pivoted back into its vertical storage or tilt-up position, the action of the spring 56 is such that the arm finger 49 is caused to ride down the inclined shoe side 53 and out of engagement therewith. The wedge shape of the shoe and the now increasing radius of curvature of the track surface 40 with respect to the pivot bearing 24 cause the frictional retarding force of the shoe 52 on the track 38 to be decreased, thereby allowing the tray to be easily and quickly pivoted to its closed position without significantly damping its movement thereto.

As was heretofore mentioned, the upper part of the track 38 is secured to the mounting plate 36 by a thumb screw 46. To increase the mechanism damping, the screw 46 is rotated in a direction to cause the upper part of the track 38 to be brought closer to the projection 44, thereby changing the track curvature with respect to the pivot bearing such that its radial distance thereto is gradually decreased as viewed from left to right in FIGUR-E 2. Since the arm 48 and spring 56 are relatively 'fixed with respect to the pivot bearing 24, the wedging action takes place earlier in the shoes path of travel and thus an increase in the damping of the tray move-ment is produced.

It will be understood, that with the track member 38 positioned on the side wall 16 such that its arc center is concentric with the bearing 24 center, the frictional force developed by the wedging action of the arm finger 49 as it rides up the inclined shoe side 53 will by itself provide a relatively consistent damping of the pivotal movement of the tray 14. However, by slightly offsetting the arc center of the track 38 from the bearing 24 center as heretofore mentioned, a gradually increased damping of the cabinet tray is provided, which can be controlled by the adjustable thumb screw 46.

From the foregoing, it will be clear that there has been provided a mechanism for a gradual or consistent damping of the pivotal movement of a member in one direction, while allowing a free and substantially undamped pivotal movement of the member in the reverse direction.

What is claimed is:

1. In a portable equipment cabinet of the type having a pair of vertically spaced side walls pivotally mounting a tray member carrying a sound reproducing apparatus therein for movement from a vertical storage position to a horizontal operating position, the combination comprismg:

an arcuately shaped track positioned on one of said side walls adjacent the tray pivot 'mounting afld II Sufrounding relation thereto;

an arm member journalled on said pivot mountingand coupled to said tray member for pivotal movement therewith;

a shoe member positioned for movement along said track;

and means including a spring coupling said arm to said shoe for urging said shoe 'into cooperative engage, ment with said track, said engagement'developing 'a frictional force for damping the pivotal movement of said tray as it pivots from its vertical storage position to its horizontal operating position.

2. The combination defined in claim 1 wherein said means further includes a projection on said arm member adjacent said shoe member for urging said shoe into cooperative engagement with said track thereby to develop a frictional force for damping the pivotal movement of said tray as it pivots from its'vertical storage position toits horizontal operating position.

3. The combination defined in claim 2 wherein a surface of said shoe member adjacent said arm member projection is inclined in a direction such that said arm member projection is caused to engage and ride Aup said inclined surface when said tray -member pivots from its vertical storage position to its horizontal operating position, and said arm member projection becomes disengaged from said inclined surface when said tray pivots from its horizontal operating position to its vertical storage position.

4. The combination defined in claim 3 wherein the arc center of said track is slightly offset from said tray pivot mounting in a direction to provide a decreased radial distance from said track to said pivot mounting in the direction of movement of said shoe when said tray pivots from its vertical storage position to its horizontal operating position.

S. The combination defined in claim 4 and further in cluding means for adjusting the position of said track on said one of said side walls so as to vary the offset of the arc center of said track with respect to said pivot mounting.

6. In a portable equipment cabinet of the type having a pair of vertically spaced side walls pivotally mounting a tray member carrying a sound reproducing apparatus therein for movement from a vertical storage position to a horizontal operating position, the combination comprising:

an arcuately shaped track positioned on one of said side walls adjacent the tray pivot mounting and in surrounding relation thereto, the arc center of said track being offset from the axis of said pivot mounting;

an arm member journalled on said pivot mounting and coupled to said tray member for pivotal movement therewith, said arm member including a finger like projection extending outwardly towards said track member;

a shoe member having a channeled underside and an inclined top side, said shoe being positioned on said track with its channel portion in sliding engagement therewith for guided movement therealong;

spring means coupling said arm member to said shoe so that said arm projection is adjacent the inclined surface of said shoe and that said projection is caused to engage and ride up said inclined surface and urge said shoe into frictional engagement with said track, said frictional engagement developing a force for damping the movement of said tray as it pivots from its vertical storage position to its horizontal operating position.

7. The combination defined in claim 6 and further including means for adjusting the position of said track on said one of said side walls so as to vary the offset ofthe arc center of said track with respect to the axis of said pivot mounting. f

(References on following page) 6 References Cited FOREIGN PATENTS UNITED STATES PATENTS 102,303 `8/ 1941 Sweden. 10/1929 Phinney 16-49 5/ 1930 Hendry 16--49 B y 11/1956 Guilbert et al 16-82 5 BO BY R. GAY, Primary Examiner.

7/ 1965 Whittom 312-8 XR J. L. KOHNEN, Assstant Examiner.

2/1966 Ammon 312-8 XR 

